There is a great need to detect and quantify various molecular species, such as polynucleotides, polypeptides, carbohydrates, lipids, and small molecules. For example, current methods of detecting a polynucleotide, such as those associated with pathogens, pathogen infection, human genes associated with diseases and disorders, altered physiology or physiological conditions, genetically modified organisms (GMOs, i.e., organisms with transgenic DNA), biowarfare agents, veterinary applications, and agricultural applications presently rely on complex methods, such as the polymerase chain reaction (PCR), nucleic acid sequence-based amplification (NASBA), transcription-mediated amplification (TMA), or branched DNA (bDNA). These methods require skilled personnel and specialized equipment. Further, the methods are generally incapable of determining the presence or quantity of polynucleotides in crude cell and tissue extracts.
There are similar difficulties in the existing immunoassays for detecting antigens. For example, antigens associated with blood coagulation disorders (e.g., F 1+2; Dade Behring, Bannockburn, Ill.), hepatitis infection (e.g., hepatitis B surface antigen; Abbott Laboratories, Abbott Park, Ill.), cancer-detection (e.g., gastrointestinal stromal tumor-specific antigens; Ventana Medical Systems, Inc., Tucson, Ariz.); acute pancreatitis (e.g., pancreatic elastase; Schebo-Biotech AG, Giessen, Germany), prostate cancer (e.g., PSA; Beckman-Coulter, Inc., Fullerton, Calif.), and the like are all based on multi-step ELISA immunoassays that require skilled personnel and specialized equipment to run.
Accordingly, there is a great need for a convenient, fast and economical method of detection, identification, and quantification of various molecules, such as polynucleotides and proteins, including polypeptides, peptides, and antigens. Reducing the complexity and increasing the reliability of such tests are among the features that would be desirably improved.